Retention of reversibly thermo-gelling timolol on the human ocular surface studied by video meniscometry

PURPOSE

To investigate the retention of reversibly thermo-gelling timolol (TG-timolol) on the human ocular surface using video meniscometry.

METHODS

The study population consisted of 14 healthy volunteers with no external eye disease. Fifteen microl TG-timolol were instilled into one eye of each subject and the same volume of aqueous, timolol ophthalmic solution was instilled in the fellow eye, in a masked fashion. Tear meniscus curvature was monitored at the center of the lower meniscus in each eye, using a newly-developed video meniscometer, before and at one-minute intervals for ten minutes after, the instillation. The radius of meniscus curvature (R) was calculated from printed video-images using the concave mirror formula. The change in R with time after instillation was compared for the two groups.

RESULTS

The change in meniscus radius with time t [defined as deltaR(t) = R(t) - R(0)] showed a significant exponential regression in both the TG-timolol and the timolol groups. There was a significant difference in the value of deltaR(5) and deltaR(10) between eyes with TG-timolol [deltaR(5) = 0.29 mm, deltaR(10) = 0.18mm] and eyes with timolol only [deltaR(5) = 0.10mm, deltaR(10) = 0.06 mm] [deltaR(5): P < 0.001, deltaR(10): P < 0.001]. The area under each regression curve of deltaR(t), an indicator of vehicle retention, was greater in the eyes treated with TG-timolol than in those receiving timolol only (2.09 vs. 0.56, P < 0.001).

CONCLUSIONS

The present study demonstrated that the reversibly thermo-gelling timolol was better retained at the ocular surface than conventional, aqueous timolol.

New Instruments for Dry Eye Diagnosis

Several non-invasive techniques for dry eye diagnosis have been developed in the past decade. These include quantitative assessment of tear volume, tear film stability, tear dynamics, and integrity of ocular surface epithelium. A combination of meniscometry and interferometry is useful for proving focal dry eye, by confirming whether or not tears at the meniscus have an effect on the ocular surface. Interferometer is also useful to evaluate tear dynamics on soft contact lenses. Fluorophotometry is useful for assessing the severity of dry eye from the view point of corneal epithelial barrier function and measuring the tear turnover rate. Both video-meibography and meibometry are useful for screening meibomian gland dysfunction. The advances in these techniques accumulate knowledge regarding pathophysiology of dry eye and allow precise diagnosis of dry eye. More targeted treatment will become feasible based on the clearer pathophysiology.

[Clinical investigation of the extrusion rate and other complications of the new Super Flex Plug punctal plug and other plugs]

PURPOSE

Currently, there are only three punctum plugs available for use in Japan [EaglePlug (EP), Eagle Flex Plug (FP), and Punctal Plug (PP)]. This study investigated the effectiveness of the newly marketed Super Flex Plug (SFP).

SUBJECTS AND METHODS

This study involved 291 eyes of 224 severe dry eye patients treated at the dry eye clinic of Kyoto Prefectural University of Medicine, Kyoto, Japan. For the SFP, EP, FP, and PP, this study compared the extrusion rate of each plug and other complications, including enlargement of the size of the punctum after extrusion, granulation, and the accumulation of soft whitish material around the plugs.

RESULTS

During the evaluation periods, the elapsed times until extrusion were significantly longer for SFP than for EP and FP(p<0.001). In all cases, there was a significant enlargement of the size of the punctum (mm) after extrusion of the SFP [0.74 +/- 0.13 (mean +/- SD)] as compared to that before insertion [0.62 +/- 0.14 (p < 0.0001)]. Granulation formed in 1.7% of the SFP cases, but the frequency was lower than that in PP cases (19%). No soft whitish material around the plug was seen in SFP-inserted eyes.

CONCLUSION

The SFP was harder to extrude, and was found to cause granulation. After extrusion of the SFP, the punctum was likely to be enlarged.

A Newly Developed Video-Meibography System Featuring a Newly Designed Probe

PURPOSE

To demonstrate the usefulness of a video-meibography system featuring our newly designed probe.

METHODS

This study utilized a newly designed probe featuring an obliquely inclined, T-shaped head containing 16 windows in the portion of the probe applied for emitting infrared light. The transilluminated structure of the meibomian gland is conducted to a highly sensitive, infrared charge-coupled device video camera and recorded digitally. The utility of the new probe was compared with the intraocular illumination probe traditionally used for meibography, both being applied to the eyelids of ten healthy volunteers and ten patients with meibomian gland dysfunction. The results were then analyzed.

RESULTS

The newly designed probe facilitated eyelid eversion and transilluminated the meibomian gland structure effectively. Moreover, subjects experienced no irritation and only limited invasiveness when the new probe was applied.

CONCLUSIONS

Our meibography system featuring the newly designed probe provided greater ease of use, an improved visualization of the meibomian gland structure, and increased comfort for patients during the examination.

Establishment of a cultivated human conjunctival epithelium as an alternative tissue source for autologous corneal epithelial transplantation

PURPOSE

The corneal epithelium is essential for maintaining corneal transparency, and efforts have been made to develop improved techniques for corneal epithelial transplantation in patients with total limbal failure. We evaluated the suitability of transplanted cultivated human conjunctival epithelium (HCjE) as a corneal epithelium replacement in rabbits with total corneal and limbal deficiency.

METHODS

HCjE cells, cultivated on human amniotic membrane (AM) to confluence and exposed to an air-liquid interface (air-lifted), were transplanted onto denuded rabbit corneas and monitored for 2 weeks. The cultivated HCjE sheet and the engrafted epithelium were analyzed by immunohistochemistry and transmission electron microscopy (TEM).

RESULTS

The transplanted HCjE remained transparent, smooth, and without epithelial defects during the follow-up period. Both the cultivated HCjE cells and the engrafted epithelium manifested five to six layers of stratified squamous epithelium similar in morphology to normal corneal epithelium. The basal cells expressed the putative stem cell markers (ABCG2 and P63) and hemidesmosome and desmosome component proteins. The cytokeratins (CK4, CK13, CK3, and CK12) and MUC4 were found in the engrafted epithelium. However, MUC5AC was not expressed. The results indicate that HCjE cultivated on AM has the potential to be used as an alternative corneal epithelium.

CONCLUSIONS

The transplantation of cultivated HCjE sheets is a promising technique for the treatment of eyes with limbal failure.

Clusters of Corneal Epithelial Cells Reside Ectopically in Human Conjunctival Epithelium

PURPOSE

The ocular surface is covered by two biologically distinct epithelia: corneal and conjunctival. The expression of keratin12 (K12) is currently considered a hallmark of cornea-type differentiation. In the current study, the biological features of K12-positive cells in human bulbar conjunctival epithelium were examined.

METHODS

Human conjunctival tissues were subjected to investigate the K12-positive cells in conjunctiva by immunostaining, in situ hybridization, Western blot analysis, reverse transcriptase-polymerase chain reaction (RT-PCR), and fluorescence-activated cell sorting (FACS). Gene expression profiling of these cells was performed with introduced amplified-fragment length polymorphism (iAFLP). To determine the presence of stem- or progenitor cells, immunostaining and colony-forming assays were performed.

RESULTS

Western blot analysis, RT-PCR revealed that K12 was expressed in conjunctival epithelium. Immunostaining analysis showed that K12-positive cells reside mainly in clusters in conjunctival epithelium. FACS analysis showed that 0.2% to 1.7% of conjunctival epithelial cells collected from the inferior bulbar conjunctiva were K12 positive. iAFLP analysis revealed that the gene expression patterns of these cells were highly similar to that of corneal epithelial cells. p63 and ABCG2 were expressed beneath the K12-positive cells. Some colony-forming cells expressed K12.

CONCLUSIONS

The K12-positive cells appear to be ectopically residing, self-maintaining corneal epithelial cells in the conjunctival epithelium.

Clinical Impact of Conjunctivochalasis on the Ocular Surface

PURPOSE

To report the clinical impact of conjunctivochalasis on the ocular surface by evaluating the effect of a new concept of conjunctivochalasis operation on the resolution of patients' symptoms and corneal epithelial damage. Also, the association of inflammation with conjunctivochalasis is examined.

PATIENTS AND METHODS

A total of 168 eyes of 131 conjunctivochalasis patients with (50 eyes) or without (118 eyes) dry eye who received the newly designed conjunctivochalasis operation were enrolled. All patients had prominent conjunctivochalasis at the lower tear meniscus and their ocular symptoms were not sufficiently controlled by the usual eyedrop therapy. Subjective symptoms of patients were assessed before and after the operation by questionnaires. Scores of corneal fluorescein staining were evaluated before and after the operation in patients with dry eye. Four samples of the lower part of conjunctiva from non-dry eye conjunctivochalasis patients were investigated by immunostaining and compared with samples from 4 normal conjunctiva and 3 conjunctiva showing inflammation due to Mooren ulcer, ocular cicatricial pemphigoid, and alkali burn.

RESULTS

The most frequent chief subjective symptoms before the operation were irritation (51.7%) and lacrimation (31.4%) in conjunctivochalasis patients without dry eye and irritation (80.0%) in those with dry eye. Improvement of the chief symptoms was obtained in 88.2% and 78.0% of these 2 patient groups, respectively. Furthermore, in patients with dry eye, corneal fluorescein staining scores (mean+/-SD) were significantly improved after the operation compared with before the operation: A (area), 0.6+/-0.7 and D (density), 0.8+/-0.9 versus A, 1.3+/-0.5 and D, 1.9+/-0.9; P<0.0001. Based on the immunostaining study, conjunctival samples from eyes with conjunctivochalasis and normal eyes showed negligible inflammation compared with those from inflamed conjunctiva.

CONCLUSIONS

This study suggests that conjunctivochalasis has a great clinical impact on the ocular surface, and the newly developed operation is very effective in resolving patient complaints and also ocular surface damage in conjunctivochalasis with dry eye. It may also be suggested that the conjunctivochalasis has a negligible association with conjunctival inflammation.

Pathological keratinisation in the conjunctival epithelium of Sjögren's syndrome

Our previous gene expression analysis suggested that conjunctival epithelial cells of Sjögren's syndrome (SS) are inclined to hyper-proliferation and keratinisation status. The goal of this study is to elucidate whether such pathological situations really exist in the conjunctival epithelium of SS. Also, involvement of inflammatory cytokines in this disease was investigated. Conjunctival tissues or cells obtained from 12 SS patients and 13 normal subjects were subjected to indirect immunostaining to analyse expression of transglutaminase 1 (TGase1), involucrin, keratins 1, 4, 10 and 13. The number of proliferative cells was also analysed by immunostaining of Ki67 antigen. Additionally, changes in gene expression of TGase1 and involucrin after stimulation by IL-1 or IFN-gamma were quantified by real-time RT-PCR. TGase1 and involucrin were up-regulated in the conjunctival epithelium of SS patients. Although not statistically significant, Ki67 positive proliferative cells were slightly increased in SS patients. IFN-gamma stimulation significantly up-regulated TGase1 and unexpectedly repressed involucrin gene expression. IL-1 did not render any significant changes in the expression of these genes. These results suggest the existence of pathological keratinisation in the conjunctival epithelium of SS and also support our hypothesis that inflammatory cytokines may be involved in the ocular surface pathological changes in SS.

[Study of change of size of the punctum before insertion and after extrusion of a punctal plug and selection of an appropriate plug for reinsertion]

PURPOSE

In cases when the reinsertion of punctal plugs is considered, enlargement of the punctum is often experienced and a larger punctal plug is sometimes required for reinsertion. We therefore investigated the change in the size of the punctum before insertion and after extrusion of a punctal plug and the selection of an appropriate punctal plug for reinsertion.

SUBJECTS AND METHODS

There were 70 cases where punctal plugs were reinserted (37 eyes from 32 patients) because of extrusion of the plugs. A retrospective study was performed with regard to the change in the size of the punctum before insertion and after extrusion of the punctal plugs, and with regard to the type of plug reinserted.

RESULTS

There were significant changes in the size of the punctum before insertion [0.70 +/- 0.09 (mean +/- standard deviation) mm] and after extrusion (0.78 +/- 0.07 mm) of the punctal plug (p < 0.001). In 22 cases of 23 cases which experienced extrusion of the 0.8 mm Eagle plug (EP; Eagle Vision), Punctal plugs (PP; FCI) of M size were selected for reinsertion, because there are no EPs larger than 0.8 mm available for reinsertion.

DISCUSSION

After extrusion of the punctal plug, the punctum is likely to be enlarged, resulting in the need to select a larger punctal plug. Therefore, cases which experienced extrusion of an EP were likely to eventually have the EP replaced by a PP during follow-up treatment.

Relationship between tear volume and tear meniscus curvature

OBJECTIVE

To investigate the relationship between tear volume and tear meniscus curvature by means of the video meniscometer.

METHODS

Eleven eyes of 11 patients with severe dry eye were studied (all female; mean +/- SD age, 66.2 +/- 7.7 years; 7 left eyes and 4 right eyes), each of whose puncta had been therapeutically occluded. Four instillations of balanced salt solution were given at intervals of 1 minute in each studied eye, with the concentration increasing in 5-microL steps from 5 to 20 microL. Before and after the instillation of balanced salt solution, tear meniscus changes were recorded by video meniscometer and radius of the meniscus was calculated from the printed images by means of the concave mirror formula.

RESULTS

The mean radius of the meniscus increased linearly with increased drop volume (r(2) = 0.65, P<.001), with mean +/- SD radius values of 0.24 +/- 0.08 mm at baseline and 0.48 +/- 0.13, 0.62 +/- 0.13, 0.84 +/- 0.26, and 1.00 +/- 0.32 mm after separate instillations of 5, 10, 15, and 20 microL of balanced salt solution, respectively. For each subject, a significantly different slope defining the relationship between instilled volume and meniscus radius was seen (0.016-0.063 mm/ microL; mean +/- SD, 0.039 +/- 0.015 mm/ microL), which was thought to depend on the difference in capacity of the fluid reservoir over the ocular surface.

CONCLUSIONS

This study confirmed that the volume of instilled eyedrops is linearly related to the resulting radius of the tear meniscus, suggesting that this radius is a useful measure in monitoring the tear volume. This is likely to have implications both for dry eye diagnosis and for confirming the efficacy of punctal occlusion in this condition.

[New surgical methods for punctal occlusion of severe tear-deficient dry eye and its outcome]

PURPOSE

Although several surgical methods for punctal occlusion have been reported, it is difficult to obtain complete punctal occlusion in all cases since recanalization of the punctum often occurs after the operation. In this report, new surgical procedures to obtain sufficient occlusion of punctum are introduced and the outcome of the present method is compared with that of previous methods.

SUBJECTS AND METHODS

Subjects were 33 severe tear-deficient dry eye patients (4 males and 29 females; mean age: 54.3 yrs.) and they were considered as candidates for punctal occlusion of both upper and lower puncta. The previous surgical punctal occlusion method had been performed in 12 cases (group A: 10 females and 2 males) and the newly-developed method was applied to 21 cases (group B : 19 females and 2 males). Corneal epithelial damage(scored with AD classification; A : area, D : density, scored from 0 to 3) was compared before and after the treatment and the control-lability of dry eye with only an artificial tear preparation was compared between the previous and the new methods. The newly-developed surgical procedures include the following steps: (1) diathermy of the epithelium of the canaliculus using a newly-designed electric needle for diathermy, (2) full removal of the epithelium of the canaliculus using a hand motor drill, (3) cutting the punctum at two opposite points parallel to the lid margin, (4) suturing the punctum to close the cut punctum with 10-0 nylon or 8-0 absorbable sutures.

RESULTS

In group A, corneal epithelial damage improved a little from A, D : 2.4, 2.1 to A, D: 1.8, 1.9 during an average of 7.2 months of alone follow-up, and only 2 of the 12 cases obtained control with eye drops. In group B, the corneal epithelial damage improved significantly from A, D : 2.1, 2.2 to A, D : 1.0, 1.3 during an average of 8.2 months of follow-up, and all cases obtained control with eye drops alone.

CONCLUSION

The new surgical methods are regarded as a more complete way of performing surgical punctal occlusion compared to previous methods.

Non-invasive methods of assessing the tear film

The interaction between the tear film and the ocular surface epithelium is crucial for the maintenance of ocular surface health; interference with this relationship may cause dry eye. Several diagnostic techniques have been developed to assess the tear film and diagnose dry eye but many of these tests are invasive and modify the parameter which they are designed to measure. Non-invasive or minimally invasive tests may overcome this problem and provide more reproducible and objective data. One test of this kind is meniscometry, which is particularly useful in assessing tear volume indirectly by measuring tear meniscus radius. The newly developed video-meniscometer, which enables calculation of the meniscus radius digitally, is useful for the diagnosis of tear-deficient dry eye. Video-meniscometry also has other applications, to the study of tear and eye drop turnover, determining the indication for punctal plugs and in demonstrating dysfunction of the tear meniscus. Interferometry of the tear film lipid layer is useful in screening and evaluating dry eye severity and in selecting dry eye candidates for punctal occlusion. It is also useful for analysing tear lipid layer pathophysiology more clearly, especially in combination with meniscometry. Meibometry is a minimally invasive technique to quantify the amount of meibomian lipid on the lid margin. Lipid is blotted onto a plastic tape and the change in optical density is used to calculate lipid uptake. Laser meibometry has increased the scope of this technique for the assessment of meibomian gland dysfunction; also, the delivery of lipids from the lid reservoir to the preocular tear film can be analysed using interferometry and laser meibometry. The present report reviews the application of these techniques to the study of tear film physiology and dry eye.

[Clinical investigation of extrusion of a new punctal plug(Flex Plug)]

PURPOSE

Punctal occlusion using punctal plugs is very effective for the treatment of tear-deficient dry eye. We compared the newly marketed Flex Plug (FP, Eagle Vision Co., Ltd.) and the Eagle Plug (EP, Eagle Vision Co., Ltd.).

SUBJECTS AND METHODS

The subjects were patients with severe tear-deficient dry eye who were treated in our dry eye clinic. FP plugs in 8 patients (9 eyes) and EP plugs in 29 patients (35 eyes) were compared during over 4 months of observation with regard to the time until extrusion and the possibility for re-insertion of the plugs.

RESULTS

During the 4 months after insertion of the plugs, the EP plugs were extruded from 35 of 51 puncta (68.6%) and the FP plugs were extruded from 4 of 13 puncta (30.8%). In the 35 EP extrusions and in the 4 FP extrusions, re-insertion was possible. The time period until extrusion was longer for FP than for EP. In all cases, for both EP and FP, pyogenic granuloma was not observed.

DISCUSSION

The extrusion rate for EP plugs was much greater than for FP plugs (68.6% to 30.8%). Pyogenic granuloma was not observed in any instance for both types of punctal plugs.

[Age-related changes in the mucocutaneous junction and the conjunctivochalasis in the lower lid margins]

PURPOSE

We investigated the age-related changes in the mucocutaneous junction and the conjunctivochalasis at the lower lid margin, and whether there is a correlation between the two or not.

SUBJECT AND METHODS

Sixty eyes of sixty patients without ocular surface disorders were examined and they were divided into six groups by age (20-29, 30-39, 40-49, 50-59, 60-69 and 70-79 years old) and sex(five males and five females in each age group). The lower lid margins were divided into three parts(the temporal third, the middle third, and the nasal third) and the anteroplacement of the mucocutaneous junction and the conjunctivochalasis were graded 0, 1, 2 and 3.

RESULT

In each part of the lower lid margins, there were significant age-related increases in both parameters(p < 0.005, p < 0.0001 respectively). Also, the grade of the anteroplacement of mucocutaneous junction increased with the grade of conjunctivochalasis.

CONCLUSION

These findings suggest that there is a relationship between the anteroplacement of the mucocutaneous junction and the conjunctivochalasis with aging.

[Comparison of extrusion rate for two different design of punctal plugs]

PURPOSE

Punctal occlusion using a silicone plug is an effective treatment for severe tear-deficient dry eye. At present, plugs from two companies are available in Japan [Eagle plug(EP); Eagle Vision, Punctal plug(PP); FCI]. We compared the extrusion rate between EP and PP in our dry eye clinic.

SUBJECTS AND METHODS

Subjects were 20 eyes of 18 patients for EP [5 eyes from 5 males, 15 eyes from 13 females, age: 58.1 +/- 17.5(mean +/- standard deviation)] and 76 eyes of 51 patients for PP (6 eyes from 5 males, 70 eyes from 46 females, age: 58.6 +/- 13.4), 62 eyes from 44 patients with Sjögren syndrome, 34 eyes from 25 patients with non-Sjögren syndrome with severe tear-deficient dry eye treated for the period of November 1996 to February 2002 in our dry eye clinic. We compared the extrusion rate for each plug and necessity of reinsertion of the plug.

RESULTS

In the examination for EP, 72.2% plugs were extruded during the follow-up periods, and the average period(59 days) until the extrusion was significantly shorter than for PP(p < 0.0001). In the examination for PP, 55.9% were extruded, and the average period until the extrusion was 287 days. Significant improvement of corneal epithelial damage was seen with PP after insertion of the plug. For the PP, reinsertion of plugs was sometimes impossible, probably because of the granulation formed inside the canaliculus, while for EP, reinsertion of the plugs was possible for all cases.

DISCUSSION

EP becomes extruded more easily than PP, and PP is seems for to form granulation more easily.

Propofol pharmacokinetics in a dwarfism patient

Pharmacokinetic information is important to control anesthetic depth. However, there are few available pharmacokinetic data of propofol in dwarfism patients. We anesthetized a dwarfism patient who underwent spinal decompression, and investigated the pharmacokinetics of propofol. The patient was a 40-year-old man suffering from muscle weakness and numbness in the arms. The operation consisted of two stages; anterior approach in the supine position and posterior approach in the prone position. We also obtained arterial blood for pharmacokinetic analysis. Distribution volume at steady-state and clearance in the supine position was 180 and 0.92 l min- 1, respectively, and in the prone position 127 and 0.74 l min- 1, respectively, in spite of a continuous infusion of dopamine. The data in the supine position were well predicted by Gepts' parameters (used in Diprifusor Zeneca Ltd, Cheshire, UK), which means the target-controlled infusion (TCI) technique can be available in the supine position, while attention is necessary to avoid overdosing when a patient is placed in the prone position.

New surgical treatment for superior limbic keratoconjunctivitis and its association with conjunctivochalasis

PURPOSE

To introduce a new surgical procedure for treating superior limbic keratoconjunctivitis (SLK) and to suggest the association of SLK with conjunctivochalasis.

DESIGN

Interventional case series.

METHODS

Six eyes of five patients with long-standing severe ocular irritation unresponsive to treatment with topical steroid and artificial tears were operated on using our new procedure. This technique consists of four steps as follows: (1) Rose bengal (RB) staining is used to localize the abnormal conjunctival area; (2) an arc-like conjunctival incision is placed from the 2 to the 10 o'clock position adjacent and distal to the RB-stained area; (3) the conjunctiva is resected to form a crescent using the arc-like incision as the base; the size of the resection is determined by conjunctival redundancy after removal of the subconjunctival connective tissue; and (4) the crescent conjunctival opening is closed with interrupted sutures. In two eyes, the new surgical procedure was performed together with surgery for inferior bulbar conjunctivochalasis.

RESULTS

In all operated eyes, RB staining had disappeared by the end of the second postoperative week; recovery from symptoms and loss of inflammation were recorded by 1 month after treatment. In the case with the longest follow-up (14 months), there was cytologic evidence of goblet cell recovery at 3 months after the operation. In another, there was normalization of the nucleo/cytoplasmic ratio of conjunctival cells without the appearance of goblet cells.

CONCLUSIONS

Our treatment very effectively resolved symptoms associated with SLK, even in eyes unresponsive to conventional therapy with eye drops. Considering that we did not address the diseased part of the conjunctiva but rather the adjacent conjunctival redundancy, we propose that superior bulbar conjunctivochalasis is involved in the pathogenesis of SLK.

Influence of latanoprost on the corneal epithelial barrier function in glaucoma patients

AIM

To evaluate the influence of topically administered latanoprost, a prostaglandin F(2alpha) analog, on the corneal epithelial barrier function.

PATIENTS AND METHODS

Twenty-four patients suffering from a glaucoma were enrolled. Ten patients without prior topical antiglaucoma medication received topical latanoprost (0.005%, once daily) for 30 days (monotherapy group); 14 patients receiving topical antiglaucoma medication also received latanoprost (0.005%, once daily) for 180 days (combination treatment group). Before and 30 days after treatment (monotherapy group) and before and 30 and 180 days after treatment (combination group), the corneal epithelial barrier function was measured by a fluorophotometric technique.

RESULTS

The fluorescein uptakes in the monotherapy group were 54.6 +/- (SE) 7.5 and 57.1 +/- 11.0 ng/ml before and 30 days after treatment, respectively (p = 0.81). In the combination group, the uptakes were 101.0 +/- 18.3 and 118.9 +/- 25.9 ng/ml (p = 0.38) and 93.4 +/- 17.5 ng/ml (p = 0.58) before and 30 and 180 days after treatment, respectively.

CONCLUSION

The corneal epithelial barrier function remained intact following the instillation of latanoprost in both groups.